Wiring & Test

You can easily wire this breakout to any microcontroller, we'll be using an Arduino. For another kind of microcontroller, just make sure it has I2C, then port the code - its pretty simple stuff!

  • Connect Vin to the power supply, 3-5V is fine. Use the same voltage that the microcontroller logic is based off of. For most Arduinos, that is 5V
  • Connect GND to common power/data ground
  • Connect the SCL pin to the I2C clock SCL pin on your Arduino. On an UNO & '328 based Arduino, this is also known as A5, on a Mega it is also known as digital 21 and on a Leonardo/Micro, digital 3
  • Connect the SDA pin to the I2C data SDA pin on your Arduino. On an UNO & '328 based Arduino, this is also known as A4, on a Mega it is also known as digital 20 and on a Leonardo/Micro, digital 2

The HDC1008 has a default I2C address of 0x40

Download Adafruit_HDC1000

To begin reading sensor data, you will need to download Adafruit_HDC1000 library from the Arduino library manager.

Open up the Arduino library manager:

Search for the Adafruit HDC1000 library and install it

We also have a great tutorial on Arduino library installation at:
http://learn.adafruit.com/adafruit-all-about-arduino-libraries-install-use

Load Demo

Open up File->Examples->Adafruit_HDC1000->HDC1000test and upload to your Arduino wired up to the sensor

Thats it! Now open up the serial terminal window at 9600 speed to begin the test.

Please note: TI has indicated that there's a 'settling' effect for the humidity and that you will need to re-hydrate the sensor once you receive it. To rehydrate it, place it in a location with 85% humidity for 24 hours or 60% humidity for 10 days.

Library Reference

The library we have is simple and easy to use

You can create the Adafruit_HDC1000 object with:

Download: file
Adafruit_HDC1000 hdc = Adafruit_HDC1000()

There are no pins to set since you must use the I2C bus!

Then initialize the sensor with:

Download: file
hdc.begin()

if you aren't using the default 0x40 i2c address, you can pass in the i2c address to begin to have it use that one instead.

Download: file
hdc.begin(0x42)

this function returns True if the sensor was found and responded correctly and False if it was not found

Once initialized, you can query the temperature in °C with

Download: file
hdc.readTemperature()

Which will return floating point (decimal + fractional) temperature. You can convert to Fahrenheit by multiplying by 1.8 and adding 32 as you have learned in grade school!

Reading the humidity is equally simple. Call

Download: file
hdc.readHumidity()

to read the humidity also as a floating point value between 0 and 100 (this reads % humidity)

This guide was first published on Jul 15, 2015. It was last updated on Jul 15, 2015. This page (Wiring & Test) was last updated on Dec 05, 2019.